Practical color reproduction processes in photography, printing and television have conventionally been limited to three-color chemical or electronic processes. Three-color processes are generally based on compromises between conflicting requirements, but yield acceptable--if not completely accurate--color image representations for many imaging applications. It has long been a goal of imaging research, however, to achieve a practical means for providing a spectrally correct color image representation instead of relying on the compromises and inherent inaccuracies of three-color processes.
Early attempts at providing spectrally correct images included the micro-dispersion method of color photography and the Lippmann method of color photography. The microdispersion method of color photography involved spreading the light from each part of a scene to be imaged into a corresponding spectrum and recording the corresponding spectrums for each part of the scene on photographic film. The Lippmann method of color photography involved the use of an emulsion-mercury interface that acted as a mirror to reflect oncoming image waves. The waves reflected off the emulsion-mercury interface then interfere with one another to produce standing waves in the emulsion. The above-described methods are discussed in greater detail in The Reproduction of Colour, by R. W. G. Hunt, 3rd Edition, 1975.
Both the Lippmann method and the micro-dispersion method, while achieving the goal of spectrally correct image reproduction, met with difficulties that limited their implementation in practical commercial systems. Accordingly, a need still exists for a practical system of obtaining a spectrally correct image representation. It is therefore an object of the invention to provide a practical method and apparatus that is capable of producing a spectrally correct image representation.